In August 2005, millions of Americans were left homeless by Hurricane Katrina, one of the most powerful hurricanes in recent history. Gore says people should expect more Category 4 and 5 hurricanes if the ocean waters continue to warm.

"Ocean-based storms [get] stronger because when the top layer of the water gets warmer, the wind speed in these hurricanes goes up and the moisture content goes up," Gore says.

In the last few years, many big hurricanes have blown ashore...but that's not the only natural disaster Americans have to worry about. Gore says the United States also recently set an all-time record for the number of tornadoes to touch down.

In other parts of the world, Japan set a record for the number of typhoons, and science textbooks had to be rewritten when the first ever South Atlantic hurricane hit Brazil. "[There are] all kinds of unusual catastrophes...it's like a nature hike through the Book of Revelations," Gore says.

While warmer oceans cause flooding in some parts of the world, they cause severe droughts in others. Gore says the warmer air holds more moisture, so when there are storm conditions, more rain falls at once. Rain is also falling in different areas. In Africa, Lake Chad—once one of the world's largest lakes—completely dried up over the last few decades, Gore says.

Drought causes dry soil and vegetation, which in turn cause more wildfires. "Today, there are five large wildfires in Southern California threatening hundreds of homes and the experts are saying, 'Look, these are the driest conditions that we've ever had,'" Gore says.